Interlock for electric switches.



PATENTED'NOV. 27', 190@ O. 0. RIDER. INTERLOCK EURv ELECTRIC SWITGHES.-

APPLICATION FILED SEPT. 28, 1905.

2 SHEETS-SHEET L v/rn/er'fof" 0/'0/7 0. /der' @www A Aug IJATENTED NOV.27, 1906.

O. O. RIDER.

INTERLOCK POR ELECTRIC SWITCHES.

APPLICATION FILED SEPT. 28, 1905.

SHEETS-SHEET 2.

Fig.

/n//eNa/ ifa/7 der UNltTED ORAN O. RIDER., SCHENEQTADY,

narran-ir raten.

NEV YORK, ASSIGNOR TO GENERAL UNTEVLOCK FOR ELECTRlC SWETCHES.

nu. seesee.

l Specification of Letters Patent.

Patented Nov. 27, 1906.

Application filed September 28.1905. Serial Noy 280.490.

Be it known that 1, OaAu O. linnen, a citizen of the United States,residing at Schenectady, county oi Schenectady, State ol New ork, haveinvented certain new and useful Improvements in lnterlocks' forlillectric Switches, of which the folhiwing is a speciiication.

The present invention relates to electric switches, and moreparticularly to iiiterlocliing means whiel'i will permit their operationonly in a definite manner.

In many electrical systen'is it is absolutely necessary inorder toinsure sal'ety to the operation of the system that the switches employedtherein he operated in a particular way. o

The present invention consists in interlocking i'nechanisn'i ol' thissort which when used with a plurality ol' switches requires theiroperation not only in a definite order, but the restoration ol' theswitch last operated to its former position hel'ore operating the next.

The invention is particularly applicable to switches employed instarting and running induction-iiiotors fand although capable. of

other uses will bedcscribed in that connection.

Referring to the accompanying drawings, in which two forms of' theinvention are disclosed, Figure l a partial sectional elevation oi" anoil-switch to which interlocking.

mechanism constructed in accordance with the present invention isapplied, the section being taken on a plane indicated by the line l l ofFig. 2. Fig. 2 is a plan View of the same, Fig. 3, a detail illustratingthe automatic trip mechanism. Figs. 4, 5, (i, and 7 illustrate differentViews ol the interlocking mechanism, Fig. 8 is a dotailedvicw`illustrating the arrangement of the switch-con- A tacts. Fig. 9 is aView oll a modified form ol' the invention, and Fig. electricconnections.

Throughout the views like characters refer to like parts.

The switch to which I have shown my invention applied is a three-phaseoil-switch ol a Well-known type and comprises a plurality of fixedcontacts l0, projecting downwardly from a horizontal supporting-framell, suitably secured to a switchboard or other support 12. The contacts1U are surrounded by l() is a diagram ot an oil-can 13, provided with asuitable insulating-lining 14 and iartitions 15voetween the contacts ofthe diiierent phases. Coperati-ng with these fixed contacts are thebridging-contacts 16, carried at the lower ends of reciprocating rods17, which are secured at their upper ends to a yoke 1 S, directlyconnected to the operating mechanism of .the switch. T he contacts 1()are provided at their upper ends with suitable terminals 20 and aremaintained out of electrical engagement with the supporting` member 1lby porcelain insulators 2l in a welleknown manner. lilach set ol'liridging-contacts 16 is operated by an independent secured to a plate23, carried on the front of the switchboard l2. The movements oil theoperaiing-levers 22 are cfmmiuiiicated to the yokes 1S and thence to thel)ridging-coiitacts by means of a system ol' links and levers. Thissystem cmnprisos a lever 2li, pivotally secured at its opposite endsto'thc yoke 18, and the vertical portion ol the l'rame 1l. This lever isrocked about itsiixcd pivotal `point so as to reciprocate the yoke 18and movable contacts oi' the switch by means of a toggle consisting ofthe links 25 26, acting between said lever and a lixed point 27 on thesupportingfframe 11. The toggle is collapsed and extended through theagency of the link 28, which is connected at its outer end to the lever22. l

The mechanism thusfar described constitutes practically two independentoperable switches, which in the starting and ruiming of aninduction-motor arc'intended to be opcratcd successively and so that atany time only one switch will be closed. ll. one ol' these switches,which may -bo designated A, be considered as the starting-switch, andthe other, which may be designated l, thi` running switch, the switch Awill irst be thrown tor has speeded up somewhat the switch A Will beopened and th(` switch l sin'iultaneously closed, so as to disconiiect-the motor l'r'om the conlpensator and connect it directly to the line.'l`his simultanmius movement of the switches is brought about by theoperator holding one switch-haver in each. hand andsimultan,eously'throwing one lever in and the other ouit. This operationwill be clearly apparent, l'rom Fig. 10, where 2t), 3U, and 3lilesigrate the three legs of a tlneewhen starting the motor, and whenthe mo-l operating -lever `22, pivotall v phase supply-circuit for theinduction-motor 32. The closing of the starting-switch A connects themotor-leads 33, 34, and 35 and the leads 36, 37, and 38, running to thecompensator 39, which is directly connected,through adisconnecting-switch S, to the three legs of the line at the points 40,41, and 42. When the ruiming-switch B is closed, the leads 33, 34, and35 of the motor are connected to the leads 43, 44, and 45, respectively,which are directly connected to thc three legs of the line through thetrip-coils, which open the switch from its running position. In such asystem it is necessary that the circuit through the compensator bebroken by opening the switch A before the switch B is closed toestablish direct connection with the line, since the reactive coil ofthe compensator would burn out or in any event waste energy. This objectis obtained by the use of the interlocking mechanism constituting thesubject of the present invention. This interlocking mechanism ispreferably located on the upper side of the supporting-frame 11 of theswitch in a position to obstruct the movement of certain parts of theoperating mechanism. According to one form of the in vention a lever 45is centrally pivoted at the point 46 to the upper side of the frame 1lmidway between the actuating-toggles of the two switches. The outer endsof thc lever 45 are adapted to engage the rear faces of tbe 'links 26 ofthe toggles, thus serving as sto-ps, and the pivot 46 is so positionedthat the outer ends of the lever will prevent both of the togglcs beingextended at the saine time. A[n other words, this lever will prevent theclosing of both switches at the same time. In the operation of themechanism this necessitates the opening of the switch A before it,ispossible to close the switch B. Now in order to insure the operation ofthe switch A before the operation of the switch B, l employ avertically-movable latch 4T, pivotcd at the point 4S to aportion ot' thesupporting-frame 1i and provided with a tail 49 at its outer end, whichmay be enga ged by a lever 50, carried by the pivot 46 and projectinginto the path of movement of the togglelink 26 of the vswitch A, Thelever 5() is drawn at all times against the link Z6 of the switch A by aspring 5l, while the opposite end of the lever 45 is drawn similarlyagainst the corresponding toggle-link of the switch B by the spring 52,these springs being connected, respectively, between the said levers andfixed points on the frame l l. The latch 47 through the agency of ashoulder 53 which normally engages the 'edge of the adjacent portion ofthe lever 45, locks said lever in the position shown in Fig. 5, andthereby prevents the closing of switch B until the latch is removed.This latter function is performed by the lever 50, which engages thetail 4'9 of the latch and removes it from latching position whenever theswitch A is closed. vWith this arrangement of the parts it will be seenthat both switches may be open at the same time, while the switch A mustbe closed before the switch B, as only one switch can remain in a closedposition at any time. The

switch-levers are placed side by side, so that one may be held in eachhand of the operator. A quick movement, simultaneously closing one andopening the other, permits transfer without stopping the motor. Forinstance, if it be assumed that both switches are open. and it isdesired ,to start up the motor the switch B cannot be thrown, since thelever 45 will be held in the position illustrated in Fig. 5 by the latch47. lt will therefore be necessary to first close the switch A., Theclosing of this switch will distend its actuating-toggle and force thi`toggle-link 26 against the lever 5() and carry it outward, so as torelease the latch from engagement with the lever This will then free thelever 45 and permit the throwing ol the switch B. The throwing of thelatter switch will in turn force its toggle-link 26 against the adjacentend ofthe lever 45, and in order that the toggli` may be properlyextended, so as to close the switch B, it will be necessariY to open theswitch A in order to remove the obstruction from the other end of thelever 45.

' Vln the system outlined when the motor 32 is once started the switch Bwill remain closed. ln order that this switch may therefore beautomatically tripped in ease ol' overload, l have illustrated awell-known type of trip-loose connection between the operatinglever 2;of this switch and the connectinglinl( 28, which is adapted to beoperated by trip-Coils 54, incloscd in a casing 55, 'formed integralwith the plate '23, carried on the face of the switchboard 12. Thesetrip devices are also of a well-known construction and comprise amovable core 56, extending downward within a Calibrating-tube 57 andprovided with a projection 58, adapted to engage a ytripping-lever 59upon the energizetion of the coil 54. A three-phase switch being shown,two of these coils 54 are employed in two legs of the circuit and eachis arranged to operate on the same trip mechanism, so as to insure atripping of the circuitrin case of dangerous conditions therein, as iswell known in the art. As it is 'unnecessary to trip the switch whilethe motor is lied through the compensator, only the running-lever isprovided with the trip-loose connection. rl`he trip-loose connectionbetween the lever 22 and its connecting-link 2S is provided by slottingthe link, as indicated at 60, so that said link may move independentlyof the lcver 22 'far enough to permit ,the switch to open under theaction of gravity. A positive connection is established between lever 22and the link Z8 by the employment of a toggle consisting of a link 61and 62. These lmember 78. A

portions, whichwill be best understood bysenses links are pivoted attheir non-adjacent ends to the lever 22 and to link 28, respectively.Fig.' 3 shows the toggle formed by these links distended and forming apositive connection between the lever and the link 28. ln

`this position the toggle is slightly overset, and its downward movementis limited by the 'engagem ent of the stops 63 on the link 62 with theupper edge of the adjacent portion of the link 28. .ln operation wheneither of the coils 54 becomes unduly energized by reason of theoverloaded condition of the circuit the trip-arm 59 will be forcedupward against the adjacent portion of the togglelink 6l with suilicientforce to breakthe toggie, and thereby permit the link 28 to be thrownoutward independently of the movement of the (merating-lever 22 inresponse to the normal tendency of the switch parts. For the purpose ofnmintaining switches closed suitable latches 64 are provided for theoperating-lcvers 22, 'lhese latches cooperate with pins 65 upon thelevers and are normally held in engaging position by the springs 66,being removed from said position by the push-pins 67, extending throughthe handle 67L :it the outer end of the lever.

ln the altermitive form of the invention (illustrated in Fig. 9) 26 and26b represent movable portions of the switches A and B, respectively,corresponding to the toggle-links 26', described heretofore, and themovementol` these members is obstructed, so to re- :luire a likemovement of the switches A and i3. The mechanisni for accomplishing thisconsists of a bolt. or pin 68, slidable within a fixed bearing 69 and ariovable member 76.

'lhe bearing 69 is secured to a flange 71 of the fixed supportingstructure, such as the supporting-frame il of the switch previouslydescribed, while the member 70 is slidable through .an opening in asinlilar flange 72. The movements of' member 7() are limited by a collar73, secured to its inner end, and a head 74, secured to its outer end.The inember 68 has secured to it a collar 75, and a coiledcompressioil-spring 76 surrounds the shank of the member 68 and bearsatits opposite ends against the collars 73 and 75. rl`he outer end ofthe member 68 is provided vwith a head 76, similar tothe head 74 on theiiieii'il m'.7(). Any sliding movement given to the member 7() will betransmittedtov the member 68 by means of a link 77, connecting thecollar 73 on theI member 7() with a lever T8, which is pivotallysupported midway of its length by a pivot 7) and pivo-tally secured:i1-.ils opposite end to the collar 75 on the 'lhe parts have definiteprocoi'isidering the operation of the device. As assumed, the member 26Lis connected with the starting-switch and the member 26" with therunni'ng-switch, 'and the parts are in the positions corresponding tothe open positions of the switches. It will be seen that the runnin-lever cannot beclosed, first by reason of t 1e square shoulder on head76a, which lies inv the path of the toggle. If now the starting-switchbe operate the member 26gt will be drawn outwardinto engagement with theinclined surface of the head 74,.,thereb T forcing the member 70 inwardto thefdottedline position. This movement will be transmitted throughthe links 7 7 and lever 78 to the memben 68, and the latter will bedrawn inward to its dotted line` position. This movement will carry thehead 76a far enough to allow the member 26b to be drawn downward a ainstthe inclined surface of said head. f this is attempted before the member26a is returned to the position illustrated, the point 8() at theopposite end of the member 68 will come up against the member 26a,

thereby stopping its movement before the` head 76a hasbeen moved farenough to allow the member 26b to clear. From this it is apparentthatthe running-switch cannot beclosed until the starting-switch isopened. It

is also clear that thestarting-switch must have been moved part way, soas to clear shoulder on 76a. yIn fact,"as already said, the' movementsof the two levers are simultaneous. As soon, however, as thestartingswitch is opened the member 26b is unobstructed, and theclosingymovement of the running -switch may be completed. This willforce the head 80 of the member 68 into the dotted-line position 80a,and, as is clearly shown, this will prevent the closing of thestarting-switch by obstructing the movement of the member 26u. However',as soon as the running-switch is opened the spring 76 will return theparts to the full-line position, and the operation above outlined may berepeated.

i From the above it will be apparent that many modifications andalterations may be made in the specific forms of' the inventiondisclosed without departing from the spirit and scope of the, presentinvention. l therefore do not wish to be limited to the exact n'iatterdisclosed, but aim to cover by the terms of the appended claims all suchaltera- .tions and modifications.

YWhat l claim new, and desire to secure by Letters Patent of the United.States, is-

l. The combination of a plurality of electric switches, and. means forcompelling both the operation of the Mvitrrlies in a definite order endthe restoration of the switch last operated to its former conditionbefore operating the next.

IOO

IIO

2. lhe combination of a plurality of electric switches, and means forcompelling both the closing of the switches in a definite order and theopening of the switch last closed before closing the next.

3. The combination of e plurality of switches, e movable stop for one ofsaid switches, means for holding seid stop in engeging position, andineens `actuated by anothei` switch to release seid holding means and tocontrol the position oi' seid stop.

4. The combination of a plurality. of electric switches, e movable stopfor each switch, means for holding the stop of one switch in engagingposition and ineens actuated by the movement of enother switch torelease seid holding ineens. y

5. The combination of a plurality of electrio switches, e pivoted stopfor each switch, ineens for holding the stop of one switch in engagingposition', and means .actuated by the movement ol' anothei` switch toreleese said holding means. v

6. The combination of a plurality of elentiio switches, e single stopinembei movable into different positions to engage the dil'eientswitches, ineens foi holding seid member in engaging position foi' oneof said switches,

sind means eetueted by the movement o enother switch to release seidholding Ineens.

7. The combination of two electric switches, comprising two movableelements, :i stop-arm Jivoted between seid elements and movable intoalternate engagement therewith, e latch for holding seid eine in thepath of movement of' one of said elen'ients,l end means actuated by theother element toI release seid lai-tolling means.

8. The eombin tion with :i paiio'f switches, of' means perinittin e freesimultaneous movement of both in o posite directions, and e lockengaging seidpmeens to eompel the operation of the switches in edifferent order and actua-ted by one of seid switches.

ln Witness whereof I have hereunto set my hand this 27th dey ofSeptember, 1905.

onlin o. einen.

1Witnesses BENJAniN BHULL. MARGARET E. Woommn

